T-SQL Stored Procedure for Looping a hierarchy with recursion

Question

i have a specific Question.

My Stored Procedure don't work correctly.. I will show you the Procedure, the database and the parameter:

ALTER PROCEDURE [dbo].[ManufacturerParentToChild] 

@ServiceProviderId int,
@CarmakerId int

AS BEGIN

SET NOCOUNT ON;

DECLARE @childSPPId int, @isDeleted bit

DECLARE ServiceProviderChildren_Cursor CURSOR FOR

SELECT ServiceProviderId, isDeleted
FROM ServiceProvider 
WHERE ParentServiceProviderId = @ServiceProviderId; 

OPEN ServiceProviderChildren_Cursor;

FETCH NEXT FROM ServiceProviderChildren_Cursor INTO @childSPPId, @isDeleted;

WHILE @@FETCH_STATUS = 0
   BEGIN
        IF @ServiceProviderId > 0
        BEGIN
            EXEC ManufacturerParentToChild @childSPPId, @CarmakerId;

            IF (SELECT COUNT(*) FROM dbo.CarmakerPartnership WHERE ServiceProviderId = @childSPPId AND CarmakerId = @CarmakerId) = 0
            BEGIN
                IF (@isDeleted = 0)
                BEGIN
                    INSERT INTO dbo.CarmakerPartnership (CarmakerId, ServiceProviderId, CreatedBy, ChangedBy, ValidityPeriodFrom, ValidityPeriodTo) VALUES (@CarmakerId, @childSPPId, SYSTEM_USER, SYSTEM_USER, '01.01.1900 00:00:00', '31.12.9999 23:59:00.000')
                END
            END 
        END
      FETCH NEXT FROM ServiceProviderChildren_Cursor INTO @childSPPId;
   END;
CLOSE ServiceProviderChildren_Cursor;
DEALLOCATE ServiceProviderChildren_Cursor; END

You See my stored Procedure above.

The Database Table Service Provider have 7 Rows:

ServiceProviderId Name ParentServiceProviderId isDeleted
1 'Parent' Null 0
2 'Child1' 1 0
3 'Child2' 1 0
4 'Child4' 2 0
5 'Child5' 3 0
6 'child6' 4 0
7 'Child7' 6 0

The Paramater get the Values:

@ServiceProviderId = 1 @CarmakerId = 5

The Procedure insert the ServiceProviderId 7, 6, 4 and 2 into CarmakerPartnerShip but don't insert 3 and 5!

Have anybody a idea why the recursive loop jump trough the childs of ServiceProviderId = 2 but don't jump trough the childs of ServiceProviderId = 3 ??

Thank you for your Help and Sorry for my bad english!!

If you have Questions you can ask me.

Best Regards

Alex

Answer 1

The fetch statement in the while block may be the cause. Currently it reads:

FETCH NEXT FROM ServiceProviderChildren_Cursor INTO @childSPPId;

try replacing it with:

FETCH NEXT FROM ServiceProviderChildren_Cursor INTO @childSPPId, @isDeleted;